An electromagnetic block-type brake currently utilized in an elevator tractor is characterized in that a double push electromagnet on the brake is installed on the housing of the driving motor in the elevator tractor, so that motor manufacturers are required to design and manufacture a mounting platform for fixing the double push electromagnet (or an electromagnet fixing base) and reserve a fixed mounting hole in the casing of the driving motor. Therefore, manufacturers that design and fabricate double push electromagnets have to design in cooperation with motor manufacturers. Such products that are cooperatively designed and separately manufactured have special purposes and limited uses, and therefore have no versatility. Also, the driving motors or electromagnetic brakes in tractors cannot be used interchangeably with driving motors or electromagnetic block-type brakes utilized in a similar type of cranes.
An electromagnetic block-type brake used in a crane is characterized in that the brake frame is a similar four-linkage rods type movable frame. The main drawback of the movable frame is that it is very difficult to adjust the gap between the braking shoes and the braking wheel, the adjustment can not be finished by ordinary maintenance staff. Because the gap between the two braking shoes and the braking wheel cannot be easily equalized, friction linings on the two braking shoes of the brake would be worn unevenly over time, which in the severe case may cause one of the braking shoes to lose its braking effect.
An existing electromagnetic block-type brake generally includes an electromagnetic brake releaser, a braking spring, and two braking shoes. The overall electromagnetic block-type brake belongs to a braking unit. In the event of accidental breakage of the braking spring, the overall braking unit would break down and immediately lead to failure of the brake, thereby inevitably resulting in severe security accidents such as falling of the suspended hanging box or the hanged objects. In fact, all the electromagnetic block-type brakes currently used have this potential security risk, and so far no effective solution has yet been brought up in the industry.